In this work, we aim to witness entanglement with trRIXS in a prototypical correlated electron system. Thus, we focus on a light-driven 1D EHM, one of the simplest fermionic models possessing strong electronic correlations and undergoing quantum phase transitions. Importantly, the EHM with mixed-sign interactions was recently identified for 1D cuprate chains [1]}, which are also well-characterized with equilibrium RIXS and provide an ideal platform for the experimental verification of our results [2]}. The EHM Hamiltonian reads as
\({\mathcal {H}} &=& -t_\mathrm {h} \sum _{i\sigma } \left[c_{i\sigma }^\dagger c_{i+1, \sigma } + \mathrm {H.c} \right] + \, U \sum _{i} n_{i\uparrow }n_{i\downarrow }\nonumber \\&& + V\sum _{ i,\sigma ,\sigma ^\prime } n_{i\sigma }n_{i+1,\sigma ^\prime } + \mathcal {H}_{\rm core},\) 
